The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Xiaoxiong Xiong - One of the best experts on this subject based on the ideXlab platform.
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impacts of the angular dependence of the solar diffuser brdf degradation factor on the snpp viirs reflective solar band on orbit Radiometric Calibration
IEEE Transactions on Geoscience and Remote Sensing, 2017Co-Authors: Ning Lei, Xiaoxiong XiongAbstract:Using an onboard sunlit solar diffuser (SD) as the primary radiance source, the visible infrared imaging radiometer suite (VIIRS) on the Suomi National Polar-orbiting Partnership satellite regularly performs Radiometric Calibration of its reflective solar bands (RSBs). The SD bidirectional reflectance distribution function (BRDF) value decreases over time. A numerical degradation factor is used to quantify the degradation and is determined by an onboard SD stability monitor (SDSM), which observes the sun and the sunlit SD at almost the same time. We had shown previously that the BRDF degradation factor was angle-dependent. Consequently, due to that the SDSM and the RSB view the SD at very different angles relative to both the solar and the SD surface normal vectors, directly applying the BRDF degradation factor determined by the SDSM to the VIIRS RSB Calibration can result in large systematic errors. We develop a phenomenological model to calculate the BRDF degradation factor for the RSB SD view from the degradation factor for the SDSM SD view. Using the yearly undulations observed in the VIIRS detector gains for the M1–M4 bands calculated with the SD BRDF degradation factor for the SDSM SD view and the difference between the VIIRS detector gains calculated from the SD and the lunar observations, we obtain the model parameter values and thus establish the relation between the BRDF degradation factors for the RSB and the SDSM SD view directions.
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assessment of snpp viirs vis nir Radiometric Calibration stability using aqua modis and invariant surface targets
IEEE Transactions on Geoscience and Remote Sensing, 2016Co-Authors: Xiaoxiong Xiong, Changyong Cao, Kwofu ChiangAbstract:The first Visible Infrared Imaging Radiometer Suite (VIIRS) is onboard the Suomi National Polar-orbiting Partnership (SNPP) satellite. As a primary sensor, it collects imagery and Radiometric measurements of the land, atmosphere, cryosphere, and oceans in the spectral regions from visible (VIS) to long-wave infrared. NASA's National Polar-orbiting Partnership (NPP) VIIRS Characterization Support Team has been actively involved in the VIIRS Radiometric and geometric Calibration to support its Science Team Principal Investigators for their independent quality assessment of VIIRS Environmental Data Records. This paper presents the performance assessment of the Radiometric Calibration stability of the VIIRS VIS and NIR spectral bands using measurements from SNPP VIIRS and Aqua MODIS simultaneous nadir overpasses and over the invariant surface targets at the Libya-4 desert and Antarctic Dome Concordia snow sites. The VIIRS sensor data records (SDRs) used in this paper are reprocessed by the NASA SNPP Land Product Evaluation and Analysis Tool Element. This paper shows that the reprocessed VIIRS SDRs have been consistently calibrated from the beginning of the mission, and the Calibration stability is similar to or better than MODIS. Results from different approaches indicate that the Calibrations of the VIIRS VIS and NIR spectral bands are maintained to be stable to within 1% over the first three-year mission. The absolute Calibration differences between VIIRS and MODIS are within 2%, with an exception for the 0.865- μm band, after correction of their spectral response differences.
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on orbit Radiometric Calibration of suomi npp viirs reflective solar bands through observations of a sunlit solar diffuser panel
IEEE Transactions on Geoscience and Remote Sensing, 2015Co-Authors: Ning Lei, Zhipeng Wang, Xiaoxiong XiongAbstract:The on-orbit Radiometric Calibration of the reflective solar bands (RSBs) of the Visible Infrared Imaging Radiometer Suite (VIIRS) aboard the Suomi National Polar-orbiting Partnership satellite is carried out primarily through observations of a fully illuminated solar diffuser (SD) panel. Accurate knowledge of the solar spectral radiance scattered from the SD is available. The sensor aperture spectral radiance is assumed to be a quadratic polynomial function of a VIIRS detector's background-subtracted response in digital number. The coefficients of the polynomial were initially determined prelaunch. Once on orbit, we assume that these coefficients change uniformly by a common Calibration factor, which is referred to as the $F$ -factor. The known solar spectral radiance scattered from a fully illuminated SD allows for the determination of these $F$ -factors. We describe the methodology and the associated algorithms used in the calculation of the RSB $F$ -factors. Our results show that the $F$ -factors change over time, with the largest change occurring at a wavelength of 862 nm (with a value of about 1.55 on day 950 after the satellite launch, relative to its value at the beginning of the launch) . In addition, we estimate the relative error standard deviations of the computed top-of-the-atmosphere reflectance at the detector pixel level. On day 950 of the mission, the relative error standard deviations are all less or equal to 0.016, except for the M11 band (band central wavelength of 2257 nm) , which has a relative error standard deviation of about 0.049 due to a very low signal-to-noise ratio.
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a new method for suomi npp viirs day night band on orbit Radiometric Calibration
IEEE Transactions on Geoscience and Remote Sensing, 2015Co-Authors: Shihyan Lee, Jeffrey Mcintire, Hassan Oudrari, Thomas Schwarting, Xiaoxiong XiongAbstract:The Suomi National Polar-orbiting Partnership Visible Infrared Imaging Radiometer Suite (S-NPP VIIRS) instrument contains a visible imaging band designed to produce imagery during both daytime and nighttime, which is called the day-night band (DNB). The DNB is a three-gain-stage backside-illuminated charge-coupled device (CCD) with four detector arrays that aggregate the individual CCD pixels into 32 different aggregation modes across scan, yielding imagery with a roughly constant horizontal sampling interval. The highest gain stage is over 100 000 times more sensitive than the lowest gain stage; the combination of the three gain stages allows for imagery with radiances ranging from 10 -10 to 10 -2 W · cm -2 · sr -1 . The initial DNB on-orbit Calibration relies on monthly sensor special operations. This offline Calibration approach results in discrete Calibration and the loss of some science data. In this paper, we will present a new Calibration method based solely on VIIRS onboard calibrators (OBCs). The calibrator data collected on the nighttime side of an orbit are used to determine the dark offset and the data collected over the daytime side of the orbit, and the day-night terminators are used to compute the cross-stage gain ratios. The results showed that the dark offset and the gain ratio derived from the initial method could be biased up to ten digital numbers (DN) and 12%, respectively, due to nighttime airglow and Earth scene stray light. The Calibration is also continuous as calibrator data are recorded for each scan. Because no special operation and offline analysis are required, this method was approved for VIIRS operational implementation to improve the DNB Radiometric Calibration and sensor on-orbit operations.
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suomi npp viirs lunar Radiometric Calibration observations
Proceedings of SPIE, 2014Co-Authors: Jon Fulbright, Zhipeng Wang, Xiaoxiong XiongAbstract:Lunar observations by the Suomi-NPP instrument VIIRS help improve our understanding of the Radiometric Calibration of the reflected solar bands (RSB). The spacecraft performs a scheduled roll maneuver approximately nine times per year to acquire lunar data at nearly constant phase angles. The instrument also captures lunar Radiometric data at other times when the instrument Space View port serendipitously points at the Moon. In this paper, we present results only from the scheduled Moon observations, comparing the observed lunar irradiance to ROLO model results to provide Calibration coefficients for each band, mirror side, and detector. These results can be evaluated directly to the primary RSB Calibration method derived from the Solar Diffuser. This paper also discusses recent improvements to our methodology for measuring the lunar irradiance, including a new method for determining the lunar position within the field of view, an all-detector Calibration methodology, and an assessment of the uncertainties in our lunar observations. This paper includes lunar observation data through June 2014.
Brian L. Markham - One of the best experts on this subject based on the ideXlab platform.
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thermal infrared Radiometric Calibration of the entire landsat 4 5 and 7 archive 1982 2010
Remote Sensing of Environment, 2012Co-Authors: John R Schott, Julia Barsi, Brian L. Markham, Simon J Hook, Jonathan Miller, Francis P Padula, Nina RaquenoAbstract:Abstract Landsat's continuing record of the thermal state of the earth's surface represents the only long term (1982 to the present) global record with spatial scales appropriate for human scale studies (i.e., tens of meters). Temperature drives many of the physical and biological processes that impact the global and local environment. As our knowledge of, and interest in, the role of temperature on these processes have grown, the value of Landsat data to monitor trends and process has also grown. The value of the Landsat thermal data archive will continue to grow as we develop more effective ways to study the long term processes and trends affecting the planet. However, in order to take proper advantage of the thermal data, we need to be able to convert the data to surface temperatures. A critical step in this process is to have the entire archive completely and consistently calibrated into absolute radiance so that it can be atmospherically compensated to surface leaving radiance and then to surface Radiometric temperature. This paper addresses the methods and procedures that have been used to perform the Radiometric Calibration of the earliest sizable thermal data set in the archive (Landsat 4 data). The completion of this effort along with the updated Calibration of the earlier (1985–1999) Landsat 5 data, also reported here, concludes a comprehensive Calibration of the Landsat thermal archive of data from 1982 to the present.
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Updated Radiometric Calibration for the Landsat-5 Thematic Mapper Reflective Bands
IEEE Transactions on Geoscience and Remote Sensing, 2008Co-Authors: Dennis L Helder, Julia Barsi, Gyanesh Chander, Brian L. Markham, Kurt Thome, Rimy MallaAbstract:The Landsat-5 Thematic Mapper (TM) has been the workhorse of the Landsat system. Launched in 1984, it continues collecting data through the time frame of this paper. Thus, it provides an invaluable link to the past history of the land features of the Earth's surface, and it becomes imperative to provide an accurate Radiometric Calibration of the reflective bands to the user community. Previous Calibration has been based on information obtained from prelaunch, the onboard calibrator, vicarious Calibration attempts, and cross-Calibration with Landsat-7. Currently, additional data sources are available to improve this Calibration. Specifically, improvements in vicarious Calibration methods and development of the use of pseudoinvariant sites for trending provide two additional independent Calibration sources. The use of these additional estimates has resulted in a consistent Calibration approach that ties together all of the available Calibration data sources. Results from this analysis indicate a simple exponential, or a constant model may be used for all bands throughout the lifetime of Landsat-5 TM. Where previously time constants for the exponential models were approximately one year, the updated model has significantly longer time constants in bands 1-3. In contrast, bands 4, 5, and 7 are shown to be best modeled by a constant. The models proposed in this paper indicate Calibration knowledge of 5% or better early in life, decreasing to nearly 2% later in life. These models have been implemented at the U.S. Geological survey earth resources observation and science (EROS) and are the default Calibration used for all Landsat TM data now distributed through EROS.
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revised landsat 5 thematic mapper Radiometric Calibration
IEEE Geoscience and Remote Sensing Letters, 2007Co-Authors: Gyanesh Chander, Brian L. Markham, Julia BarsiAbstract:Effective April 2, 2007, the Radiometric Calibration of Landsat-5 (L5) Thematic Mapper (TM) data that are processed and distributed by the U.S. Geological Survey (USGS) Center for Earth Resources Observation and Science (EROS) will be updated. The lifetime gain model that was implemented on May 5, 2003, for the reflective bands (1-5, 7) will be replaced by a new lifetime Radiometric-Calibration curve that is derived from the instrument's response to pseudoinvariant desert sites and from cross Calibration with the Landsat-7 (L7) Enhanced TM Plus (ETM+). Although this Calibration update applies to all archived and future L5 TM data, the principal improvements in the Calibration are for the data acquired during the first eight years of the mission (1984-1991), where the changes in the instrument-gain values are as much as 15%. The Radiometric scaling coefficients for bands 1 and 2 for approximately the first eight years of the mission have also been changed. Users will need to apply these new coefficients to convert the calibrated data product digital numbers to radiance. The scaling coefficients for the other bands have not changed.
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evaluation of the landsat 5 tm Radiometric Calibration history using desert test sites
Remote Sensing, 2006Co-Authors: Brian L. Markham, Dennis L Helder, Julia Barsi, Kurtis J Thome, John L BarkerAbstract:The U.S. Radiometric Calibration procedure for the reflective bands of the Landsat-5 Thematic Mapper was updated in May 2003. This update was based on a model of the performance of the instrument developed from its response to the best-behaved internal Calibration lamp and from a cross Calibration with Landsat-7 ETM+ that occurred in June 1999. Since this update was performed, there have been continued attempts to validate the model. These validations have relied primarily upon data acquired over deserts of the world. These studies have been limited by the amount of data available over any one site for the 22-year life of the mission. Initial attempts over the desert Southwest of the United States were inconclusive, though they were suggestive of additional degradation occurring in the shorter wavelength channels. More recently, significant holdings from European Space Agency of data over North Africa have been made available for analysis. The North Africa test area results to date for one site in Libya are considerably less noisy than the North American datasets. They indicate an exponential-like decay of about 19%, 16%, 8% and 4% for TM bands 1, 2, 3 and 4, with the degradation, at least in bands 1 and 2 occurring throughout the mission. The current model shows changes of roughly the same magnitude, but with the change occurring more rapidly so that nearly all the change is completed in 4 years. These results are generally consistent with independent work going on outside of this effort. Additional sites are being analyzed as data become available.
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Landsat-5 TM reflective-band absolute Radiometric Calibration
IEEE Transactions on Geoscience and Remote Sensing, 2004Co-Authors: Gyanesh Chander, Dennis L Helder, Brian L. Markham, Kurtis J Thome, E. Micijevic, J.d. Dewald, Edward Kaita, T.a. RugglesAbstract:The Landsat-5 Thematic Mapper (TM) sensor provides the longest running continuous dataset of moderate spatial resolution remote sensing imagery, dating back to its launch in March 1984. Historically, the Radiometric Calibration procedure for this imagery used the instrument's response to the Internal Calibrator (IC) on a scene-by-scene basis to determine the gain and offset of each detector. Due to observed degradations in the IC, a new procedure was implemented for U.S.-processed data in May 2003. This new Calibration procedure is based on a lifetime Radiometric Calibration model for the instrument's reflective bands (1-5 and 7) and is derived, in part, from the IC response without the related degradation effects and is tied to the cross Calibration with the Landsat-7 Enhanced Thematic Mapper Plus. Reflective-band absolute Radiometric accuracy of the instrument tends to be on the order of 7% to 10%, based on a variety of Calibration methods.
Dennis L Helder - One of the best experts on this subject based on the ideXlab platform.
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the ground based absolute Radiometric Calibration of landsat 8 oli
Remote Sensing, 2015Co-Authors: Jeffrey S Czaplamyers, Dennis L Helder, Kurtis Thome, Joel Mccorkel, Stuart F. Biggar, David Aaron, Nikolaus J Anderson, Larry Leigh, Nischal MishraAbstract:This paper presents the vicarious Calibration results of Landsat 8 OLI that were obtained using the reflectance-based approach at test sites in Nevada, California, Arizona, and South Dakota, USA. Additional data were obtained using the Radiometric Calibration Test Site, which is a suite of instruments located at Railroad Valley, Nevada, USA. The results for the top-of-atmosphere spectral radiance show an average difference of −2.7, −0.8, 1.5, 2.0, 0.0, 3.6, 5.8, and 0.7% in OLI bands 1–8 as compared to an average of all of the ground-based measurements. The top-of-atmosphere spectral reflectance shows an average difference of 1.6, 1.3, 2.0, 1.9, 0.9, 2.1, 3.1, and 2.1% from the ground-based measurements. Except for OLI band 7, the spectral radiance results are generally within ±5% of the design specifications, and the reflectance results are generally within ±3% of the design specifications. The results from the data collected during the tandem Landsat 7 and 8 flight in March 2013 indicate that ETM+ and OLI agree to each other to within ±2% in similar bands in top-of-atmosphere spectral radiance, and to within ±4% in top-of-atmosphere spectral reflectance.
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the ground based absolute Radiometric Calibration of landsat 8 oli
Remote Sensing, 2015Co-Authors: Jeffrey S Czaplamyers, Dennis L Helder, Kurtis Thome, Joel Mccorkel, Stuart F. Biggar, David Aaron, Larry Leigh, Nikolaus Anderson, Nischal MishraAbstract:This paper presents the vicarious Calibration results of Landsat 8 OLI that were obtained using the reflectance-based approach at test sites in Nevada, California, Arizona, and South Dakota, USA. Additional data were obtained using the Radiometric Calibration Test Site, which is a suite of instruments located at Railroad Valley, Nevada, USA. The results for the top-of-atmosphere spectral radiance show an average difference of −2.7, −0.8, 1.5, 2.0, 0.0, 3.6, 5.8, and 0.7% in OLI bands 1–8 as compared to an average of all of the ground-based measurements. The top-of-atmosphere spectral reflectance shows an average difference of 1.6, 1.3, 2.0, 1.9, 0.9, 2.1, 3.1, and 2.1% from the ground-based measurements. Except for OLI band 7, the spectral radiance results are generally within ±5% of the design specifications, and the reflectance results are generally within ±3% of the design specifications. The results from the data collected during the tandem Landsat 7 and 8 flight in March 2013 indicate that ETM+ and OLI agree to each other to within ±2% in similar bands in top-of-atmosphere spectral radiance, and to within ±4% in top-of-atmosphere spectral reflectance.
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Radiometric Calibration of the Landsat MSS Sensor Series
IEEE Transactions on Geoscience and Remote Sensing, 2012Co-Authors: Dennis L Helder, David Aaron, Sadhana Karki, Rajendra Bhatt, Esad Micijevic, Benjamin JasinskiAbstract:Multispectral remote sensing of the Earth using Landsat sensors was ushered on July 23, 1972, with the launch of Landsat-1. Following that success, four more Landsat satellites were launched, and each of these carried the Multispectral Scanner System (MSS). These five sensors provided the only consistent multispectral space-based imagery of the Earth's surface from 1972 to 1982. This work focuses on developing both a consistent and absolute Radiometric Calibration of this sensor system. Cross-Calibration of the MSS was performed through the use of pseudoinvariant Calibration sites (PICSs). Since these sites have been shown to be stable for long periods of time, changes in MSS observations of these sites were attributed to changes in the sensors themselves. In addition, simultaneous data collections were available for some MSS sensor pairs, and these were also used for cross-Calibration. Results indicated substantial differences existed between instruments, up to 16%, and these were reduced to 5% or less across all MSS sensors and bands. Lastly, this paper takes the Calibration through the final step and places the MSS sensors on an absolute Radiometric scale. The methodology used to achieve this was based on simultaneous data collections by the Landsat-5 MSS and Thematic Mapper (TM) instruments. Through analysis of image data from a PICS location and through compensating for the spectral differences between the two instruments, the Landsat-5 MSS sensor was placed on an absolute Radiometric scale based on the Landsat-5 TM sensor. Uncertainties associated with this Calibration are considered to be less than 5%.
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Updated Radiometric Calibration for the Landsat-5 Thematic Mapper Reflective Bands
IEEE Transactions on Geoscience and Remote Sensing, 2008Co-Authors: Dennis L Helder, Julia Barsi, Gyanesh Chander, Brian L. Markham, Kurt Thome, Rimy MallaAbstract:The Landsat-5 Thematic Mapper (TM) has been the workhorse of the Landsat system. Launched in 1984, it continues collecting data through the time frame of this paper. Thus, it provides an invaluable link to the past history of the land features of the Earth's surface, and it becomes imperative to provide an accurate Radiometric Calibration of the reflective bands to the user community. Previous Calibration has been based on information obtained from prelaunch, the onboard calibrator, vicarious Calibration attempts, and cross-Calibration with Landsat-7. Currently, additional data sources are available to improve this Calibration. Specifically, improvements in vicarious Calibration methods and development of the use of pseudoinvariant sites for trending provide two additional independent Calibration sources. The use of these additional estimates has resulted in a consistent Calibration approach that ties together all of the available Calibration data sources. Results from this analysis indicate a simple exponential, or a constant model may be used for all bands throughout the lifetime of Landsat-5 TM. Where previously time constants for the exponential models were approximately one year, the updated model has significantly longer time constants in bands 1-3. In contrast, bands 4, 5, and 7 are shown to be best modeled by a constant. The models proposed in this paper indicate Calibration knowledge of 5% or better early in life, decreasing to nearly 2% later in life. These models have been implemented at the U.S. Geological survey earth resources observation and science (EROS) and are the default Calibration used for all Landsat TM data now distributed through EROS.
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evaluation of the landsat 5 tm Radiometric Calibration history using desert test sites
Remote Sensing, 2006Co-Authors: Brian L. Markham, Dennis L Helder, Julia Barsi, Kurtis J Thome, John L BarkerAbstract:The U.S. Radiometric Calibration procedure for the reflective bands of the Landsat-5 Thematic Mapper was updated in May 2003. This update was based on a model of the performance of the instrument developed from its response to the best-behaved internal Calibration lamp and from a cross Calibration with Landsat-7 ETM+ that occurred in June 1999. Since this update was performed, there have been continued attempts to validate the model. These validations have relied primarily upon data acquired over deserts of the world. These studies have been limited by the amount of data available over any one site for the 22-year life of the mission. Initial attempts over the desert Southwest of the United States were inconclusive, though they were suggestive of additional degradation occurring in the shorter wavelength channels. More recently, significant holdings from European Space Agency of data over North Africa have been made available for analysis. The North Africa test area results to date for one site in Libya are considerably less noisy than the North American datasets. They indicate an exponential-like decay of about 19%, 16%, 8% and 4% for TM bands 1, 2, 3 and 4, with the degradation, at least in bands 1 and 2 occurring throughout the mission. The current model shows changes of roughly the same magnitude, but with the change occurring more rapidly so that nearly all the change is completed in 4 years. These results are generally consistent with independent work going on outside of this effort. Additional sites are being analyzed as data become available.
Julia Barsi - One of the best experts on this subject based on the ideXlab platform.
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thermal infrared Radiometric Calibration of the entire landsat 4 5 and 7 archive 1982 2010
Remote Sensing of Environment, 2012Co-Authors: John R Schott, Julia Barsi, Brian L. Markham, Simon J Hook, Jonathan Miller, Francis P Padula, Nina RaquenoAbstract:Abstract Landsat's continuing record of the thermal state of the earth's surface represents the only long term (1982 to the present) global record with spatial scales appropriate for human scale studies (i.e., tens of meters). Temperature drives many of the physical and biological processes that impact the global and local environment. As our knowledge of, and interest in, the role of temperature on these processes have grown, the value of Landsat data to monitor trends and process has also grown. The value of the Landsat thermal data archive will continue to grow as we develop more effective ways to study the long term processes and trends affecting the planet. However, in order to take proper advantage of the thermal data, we need to be able to convert the data to surface temperatures. A critical step in this process is to have the entire archive completely and consistently calibrated into absolute radiance so that it can be atmospherically compensated to surface leaving radiance and then to surface Radiometric temperature. This paper addresses the methods and procedures that have been used to perform the Radiometric Calibration of the earliest sizable thermal data set in the archive (Landsat 4 data). The completion of this effort along with the updated Calibration of the earlier (1985–1999) Landsat 5 data, also reported here, concludes a comprehensive Calibration of the Landsat thermal archive of data from 1982 to the present.
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Updated Radiometric Calibration for the Landsat-5 Thematic Mapper Reflective Bands
IEEE Transactions on Geoscience and Remote Sensing, 2008Co-Authors: Dennis L Helder, Julia Barsi, Gyanesh Chander, Brian L. Markham, Kurt Thome, Rimy MallaAbstract:The Landsat-5 Thematic Mapper (TM) has been the workhorse of the Landsat system. Launched in 1984, it continues collecting data through the time frame of this paper. Thus, it provides an invaluable link to the past history of the land features of the Earth's surface, and it becomes imperative to provide an accurate Radiometric Calibration of the reflective bands to the user community. Previous Calibration has been based on information obtained from prelaunch, the onboard calibrator, vicarious Calibration attempts, and cross-Calibration with Landsat-7. Currently, additional data sources are available to improve this Calibration. Specifically, improvements in vicarious Calibration methods and development of the use of pseudoinvariant sites for trending provide two additional independent Calibration sources. The use of these additional estimates has resulted in a consistent Calibration approach that ties together all of the available Calibration data sources. Results from this analysis indicate a simple exponential, or a constant model may be used for all bands throughout the lifetime of Landsat-5 TM. Where previously time constants for the exponential models were approximately one year, the updated model has significantly longer time constants in bands 1-3. In contrast, bands 4, 5, and 7 are shown to be best modeled by a constant. The models proposed in this paper indicate Calibration knowledge of 5% or better early in life, decreasing to nearly 2% later in life. These models have been implemented at the U.S. Geological survey earth resources observation and science (EROS) and are the default Calibration used for all Landsat TM data now distributed through EROS.
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prime candidate earth targets for the post launch Radiometric Calibration of space based optical imaging instruments
Proceedings of SPIE, 2007Co-Authors: Philippe M Teillet, Julia Barsi, Gyanesh Chander, Kurt ThomeAbstract:This paper provides a comprehensive list of prime candidate terrestrial targets for consideration as benchmark sites for the post-launch Radiometric Calibration of space-based instruments. The key characteristics of suitable sites are outlined primarily with respect to selection criteria, spatial uniformity, and temporal stability. The establishment and utilization of such benchmark sites is considered an important element of the Radiometric traceability of satellite image data products for use in the accurate monitoring of environmental change.
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revised landsat 5 thematic mapper Radiometric Calibration
IEEE Geoscience and Remote Sensing Letters, 2007Co-Authors: Gyanesh Chander, Brian L. Markham, Julia BarsiAbstract:Effective April 2, 2007, the Radiometric Calibration of Landsat-5 (L5) Thematic Mapper (TM) data that are processed and distributed by the U.S. Geological Survey (USGS) Center for Earth Resources Observation and Science (EROS) will be updated. The lifetime gain model that was implemented on May 5, 2003, for the reflective bands (1-5, 7) will be replaced by a new lifetime Radiometric-Calibration curve that is derived from the instrument's response to pseudoinvariant desert sites and from cross Calibration with the Landsat-7 (L7) Enhanced TM Plus (ETM+). Although this Calibration update applies to all archived and future L5 TM data, the principal improvements in the Calibration are for the data acquired during the first eight years of the mission (1984-1991), where the changes in the instrument-gain values are as much as 15%. The Radiometric scaling coefficients for bands 1 and 2 for approximately the first eight years of the mission have also been changed. Users will need to apply these new coefficients to convert the calibrated data product digital numbers to radiance. The scaling coefficients for the other bands have not changed.
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evaluation of the landsat 5 tm Radiometric Calibration history using desert test sites
Remote Sensing, 2006Co-Authors: Brian L. Markham, Dennis L Helder, Julia Barsi, Kurtis J Thome, John L BarkerAbstract:The U.S. Radiometric Calibration procedure for the reflective bands of the Landsat-5 Thematic Mapper was updated in May 2003. This update was based on a model of the performance of the instrument developed from its response to the best-behaved internal Calibration lamp and from a cross Calibration with Landsat-7 ETM+ that occurred in June 1999. Since this update was performed, there have been continued attempts to validate the model. These validations have relied primarily upon data acquired over deserts of the world. These studies have been limited by the amount of data available over any one site for the 22-year life of the mission. Initial attempts over the desert Southwest of the United States were inconclusive, though they were suggestive of additional degradation occurring in the shorter wavelength channels. More recently, significant holdings from European Space Agency of data over North Africa have been made available for analysis. The North Africa test area results to date for one site in Libya are considerably less noisy than the North American datasets. They indicate an exponential-like decay of about 19%, 16%, 8% and 4% for TM bands 1, 2, 3 and 4, with the degradation, at least in bands 1 and 2 occurring throughout the mission. The current model shows changes of roughly the same magnitude, but with the change occurring more rapidly so that nearly all the change is completed in 4 years. These results are generally consistent with independent work going on outside of this effort. Additional sites are being analyzed as data become available.
Kurtis J Thome - One of the best experts on this subject based on the ideXlab platform.
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evaluation of the landsat 5 tm Radiometric Calibration history using desert test sites
Remote Sensing, 2006Co-Authors: Brian L. Markham, Dennis L Helder, Julia Barsi, Kurtis J Thome, John L BarkerAbstract:The U.S. Radiometric Calibration procedure for the reflective bands of the Landsat-5 Thematic Mapper was updated in May 2003. This update was based on a model of the performance of the instrument developed from its response to the best-behaved internal Calibration lamp and from a cross Calibration with Landsat-7 ETM+ that occurred in June 1999. Since this update was performed, there have been continued attempts to validate the model. These validations have relied primarily upon data acquired over deserts of the world. These studies have been limited by the amount of data available over any one site for the 22-year life of the mission. Initial attempts over the desert Southwest of the United States were inconclusive, though they were suggestive of additional degradation occurring in the shorter wavelength channels. More recently, significant holdings from European Space Agency of data over North Africa have been made available for analysis. The North Africa test area results to date for one site in Libya are considerably less noisy than the North American datasets. They indicate an exponential-like decay of about 19%, 16%, 8% and 4% for TM bands 1, 2, 3 and 4, with the degradation, at least in bands 1 and 2 occurring throughout the mission. The current model shows changes of roughly the same magnitude, but with the change occurring more rapidly so that nearly all the change is completed in 4 years. These results are generally consistent with independent work going on outside of this effort. Additional sites are being analyzed as data become available.
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landsat 5 tm and landsat 7 etm absolute Radiometric Calibration using the reflectance based method
IEEE Transactions on Geoscience and Remote Sensing, 2004Co-Authors: Kurtis J Thome, Dennis L Helder, David Aaron, J.d. DewaldAbstract:The reflectance-based method of vicarious Calibration has been used for the absolute Radiometric Calibration of the Landsat series of sensors since the launch of Landsat-4. The reflectance-based method relies on ground-based measurements of the surface reflectance and atmospheric conditions at a selected test site nearly coincident with the imaging of that site by the sensor of interest. The results of this approach are presented here for Landsat-5 Thematic Mapper (TM) and Landsat-7 Enhanced Thematic Mapper Plus (ETM+). The data have been collected by two groups, one from the University of Arizona and the other from South Dakota State University. The test sites used by the University of Arizona group for this work are the Railroad Valley Playa, Lunar Lake Playa, and Roach Lake Playa all of which are in Nevada, Ivanpah Playa in California, and White Sands Missile Range, New Mexico. The test site for the South Dakota State group is a grass site in Brookings, SD. The gains derived from dates using these sites spanning the period from 1984 to 2003 are presented for TM and for the period of 1999 to 2003 for ETM+. Differences between the two groups are less than the combined uncertainties of the methods, and the data are thus treated as a single dataset. The results of these vicarious data indicate that there has been no degradation apparent in TM since 1995 and in ETM+ since launch. Agreement between the reflectance-based results and the preflight Calibration of ETM+ is better than 4% in all bands, and the standard deviation of the average difference indicates a precision of the reflectance-based method on the order of 3%.
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Landsat-5 TM reflective-band absolute Radiometric Calibration
IEEE Transactions on Geoscience and Remote Sensing, 2004Co-Authors: Gyanesh Chander, Dennis L Helder, Brian L. Markham, Kurtis J Thome, E. Micijevic, J.d. Dewald, Edward Kaita, T.a. RugglesAbstract:The Landsat-5 Thematic Mapper (TM) sensor provides the longest running continuous dataset of moderate spatial resolution remote sensing imagery, dating back to its launch in March 1984. Historically, the Radiometric Calibration procedure for this imagery used the instrument's response to the Internal Calibrator (IC) on a scene-by-scene basis to determine the gain and offset of each detector. Due to observed degradations in the IC, a new procedure was implemented for U.S.-processed data in May 2003. This new Calibration procedure is based on a lifetime Radiometric Calibration model for the instrument's reflective bands (1-5 and 7) and is derived, in part, from the IC response without the related degradation effects and is tied to the cross Calibration with the Landsat-7 Enhanced Thematic Mapper Plus. Reflective-band absolute Radiometric accuracy of the instrument tends to be on the order of 7% to 10%, based on a variety of Calibration methods.
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absolute Radiometric Calibration of landsat 7 etm using the reflectance based method
Remote Sensing of Environment, 2001Co-Authors: Kurtis J ThomeAbstract:Abstract A key to the continuation of quantitative data from the Landsat series of sensors is the Radiometric understanding of the sensor. Vicarious Calibration methods are one approach that has been used successfully for the absolute Radiometric Calibration of Thematic Mapper (TM). One of these vicarious methods is the reflectance-based approach that is applied here to the Radiometric Calibration of the Enhanced Thematic Mapper Plus (ETM+) sensor on the Landsat 7 platform. This method is described for application to ETM+. Results from ground-based measurements of atmospheric conditions and surface reflectance made at Railroad Valley Playa, Nevada, Roach Lake Playa, Nevada, and White Sands Missile Range, New Mexico are presented including descriptions of the test sites. The gains derived from four dates using these sites spanning the period from June 1999 to October 1999 agree to within 5% of each other and to better than 7% with the prelaunch, laboratory-derived gains. This is within the combined 5% uncertainty of the prelaunch values and the estimated 3–5% uncertainty of the reflectance-based method. The gains determined from the reflectance-based method are all lower than the prelaunch values for bands 1–5 and the values for band 7 exceed the prelaunch gains. These biases could be caused by errors in the treatment of atmospheric aerosols at shorter wavelengths and uncertainties in the assumed solar irradiances used to convert the relative radiances to absolute values at longer wavelengths.
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absolute Radiometric Calibration of landsat 7 etm using the reflectance based method
Remote Sensing of Environment, 2001Co-Authors: Kurtis J ThomeAbstract:Abstract A key to the continuation of quantitative data from the Landsat series of sensors is the Radiometric understanding of the sensor. Vicarious Calibration methods are one approach that has been used successfully for the absolute Radiometric Calibration of Thematic Mapper (TM). One of these vicarious methods is the reflectance-based approach that is applied here to the Radiometric Calibration of the Enhanced Thematic Mapper Plus (ETM+) sensor on the Landsat 7 platform. This method is described for application to ETM+. Results from ground-based measurements of atmospheric conditions and surface reflectance made at Railroad Valley Playa, Nevada, Roach Lake Playa, Nevada, and White Sands Missile Range, New Mexico are presented including descriptions of the test sites. The gains derived from four dates using these sites spanning the period from June 1999 to October 1999 agree to within 5% of each other and to better than 7% with the prelaunch, laboratory-derived gains. This is within the combined 5% uncertainty of the prelaunch values and the estimated 3–5% uncertainty of the reflectance-based method. The gains determined from the reflectance-based method are all lower than the prelaunch values for bands 1–5 and the values for band 7 exceed the prelaunch gains. These biases could be caused by errors in the treatment of atmospheric aerosols at shorter wavelengths and uncertainties in the assumed solar irradiances used to convert the relative radiances to absolute values at longer wavelengths.
